iOS debugging tools are essential when developing applications for the system. It’s almost impossible to create a bug-free app without testing. While testing, you will need these tools to track down the source of any issues you encounter. Issues with the app will not only impact the user experience but they also violate App Store’s guidelines, making it much harder to publish.
Olga Weis
Last updated Dec 26, 2023
Debug tools fulfill various roles, and even within the same category, different tools may have their own individual workflow. Here, you can learn about some of the best mobile app debugging software options.
Your choice of debugging tools will depend on your workflow and your budget. It’s also worth remembering that these are not mutually exclusive choices - in fact, having a variety of debugging software can be necessary. Here are some tips:
As Apple’s official development environment, Xcode includes a complete, but moderate kit of features to debug an application for iOS. These include a complete simulator, breakpoints, and even a mode that highlights slower UI elements during runtime. It’s also capable of iPhone USB debugging.
★ Features
In Xcode, breakpoints can be customized to execute a specific action when reaching them or to add specific conditions. You can see the called methods in the Navigator and see the class contents with Quick Look. This debug tool is also equipped with some UI optimization instruments, such as the Color Blended Layers and an Interface Hierarchy browser.
★ Use Cases
Xcode sets the development and testing baseline, and many other apps only modify it and provide additional functionality. Debugging is not the main focus, not that it should be in a standard integrated suite.
LLDB is the default debugger in Xcode. The debugging features in Xcode are all based on it, even if they’re accessed in the GUI. When the breakpoint system proves insufficient, it may be time to move on to issuing direct LLDB commands in the terminal.
★ Features
By using LLDB, you can attach to processes, create variable watchpoints, examine variables, backtrace threads, and much more. With the use of arguments, it can do pretty specific things, such as waiting for a process to launch before attaching. LLDB can be used for USB debugging iPhone tasks, or it can be applied to a simulator instance.
★ Use Cases
LLDB is a lot more complete than the options available from Xcode’s interface, and not particularly hard to learn. True to its name, it’s the only native option to find low-level issues that can’t be obviously found in your code.
Another part of Xcode, Instruments is focused purely on data collection and statistics. And the bulk of this data will be about resource use. Instruments tracks the use of CPU power, battery charge, RAM, and such.
★ Features
Instruments doesn’t just collect data, but it also allows you to filter and display it for maximum convenience. The gathered information is summarized visually on a timeline, with a graph for each tracked stat. When you find a suspect place on one of the graphs, you can view the selection in detail.
★ Use Cases
Using Instruments is a good first step to optimizing your app’s performance. Memory leaks and processor overuse are every bit as important to target as errors and crashes. And often, they can only be found statistically.
The Simulator is included as a part of Xcode, and you can download an iOS runtime to run your apps in a virtual environment, without the need for an additional device. It can be useful for simple hands-on testing or bug hunting.
★ Features
The simulator can be interacted with through simple controls, and it can receive data from the user’s system. This application aims to be as authentic as possible, so it provides options for hard-to-simulate situations, such as falls, location changes, and Face ID.
★ Use Cases
While it’s an immensely, obviously useful tool, it’s also important to recognize the differences between a real device and a simulator instance. The main differences that Apple documentation warns about have to do with hardware, so don’t use it as a benchmark.
FlexiHub virtualizes USB devices that are attached to a computer and makes them accessible from a different computer over the network. The range of devices includes iPhones and iPads. This has some novel and impressive uses in the field of app development, including Xcode remote debugging.
★ Features
An attached device will be shared with other FlexiHub users on the same network through an encrypted connection, ensuring data safety. The device can be password-protected or temporarily locked to prevent its use. Importantly, FlexiHub is completely cross-platform, so a Windows or Linux computer can act as the server for iOS devices, while a developer uses them on a macOS machine.
★ Use Cases
FlexiHub allows remote development teams to have a centralized base of devices to tap into and test their iOS software. This provides a more realistic alternative to the built-in simulator, without actually creating the need for developers to get and maintain their own hardware.
Reveal by Itty Bitty Apps is, in lots of ways, similar to Xcode’s Debug View Hierarchy. One major difference is that it needs to be linked with an app in order to analyze it. And yet, it’s still worth using. Let’s explore the reasons why.
★ Features
Much care has been poured into Reveal’s interface, making it easier to find the needed UI elements. Once you do, their attributes can actually be changed on the fly. Layout problems are detected and highlighted automatically.
★ Use Cases
Reveal can be a simple improvement to the workflow, thanks to its interface. It can help with a thorough look into an unfamiliar project. And, of course, the quick adjustment of element dimensions and other values is a way to experiment with the interface.
Charles is a network monitoring tool that keeps track of requests and responses. Once again, this is a role that is also fulfilled by the built-in Instruments. Charles isn’t just an alternative, though; when it comes to HTTP and SSL debugging, it does a lot more.
★ Features
This debugging tool can actually send its own requests to the tested app. They can be automatically re-sent to quickly see how modifications affect the network behavior of the app. Charles can be set up in the middle of an SSL connection, providing highly useful data that is otherwise locked.
★ Use Cases
Developers of any internet application, especially a secure one, can get a lot of use out of Charles. As long as they know how to interpret the output, they will be able to detect HTTP and SSL connectivity issues.
Bugfender is a solution that sends error reports and logs in general from devices to a cloud service, as a form of iOS remote debugging. It’s not really intended for use on a single device, but rather as a way to gather data relevant to debugging from users. They turn into testers, in a way. The app has to be ready to ship, though - it’s not for early development stages.
★ Features
In addition to simple crash logs, Bugfender tracks app performance, and records everything that could indicate the cause of the error. Crash data can be congregated into a graph that’s helpful if you want to see which devices cause the most trouble. Bugfender provides its own SDK to integrate these functions into apps.
★ Use Cases
While it may seem like Bugfender is only catered to large commercial users, it actually has a free plan for independent developers. This is an opportunity for small or one-person companies to implement debugging practices on par with those used by major companies.
Crashlytics is also a reporting tool, and it’s a part of Google Firebase, but the rest of the platform doesn’t need to be used. The tool is inserted into apps through the use of an SDK. Crashlytics is free and unlimited.
★ Features
The features of Crashalytics generally revolve around data crunching and convenience. Once again, you’ll see report graphs and general statistics. This debugging tool is friendly to popular project management tools, such as Jira.
★ Use Cases
If you heavily use Firebase in your development process, Crashlytics is a no-brainer, but it also has plenty of merits to justify using this tool by itself. Take note that it only gets data connected to crashes. You won’t be able to detect performance issues or non-fatal bugs this way.
Raygun is a crash reporting and user monitoring tool. It collects information both about fatal errors and performance. Data can be gathered broadly, and then the findings can be used to narrow down the range of tracked devices and get more metrics from them.
★ Features
Raygun borrows a lot of its tools from the realm of web UX. The metrics are related to app loading times, whether it’s a particular element or in general. As for the error reports, they are condensed into viewable graphics, and allow the developer to search their detailed information for the root cause.
★ Use Cases
With a steep starting price of $40/month, Raygun is aimed at small businesses that can afford the cost, and advanced features require a more expensive plan. It has the same use as any other error and performance-tracking app - providing developers with a lead that they can work on.
As you can see, many aspects of iOS apps benefit from debugging, if not outright require it. The code itself, the UI, resources, and even network activity - depending on the functionality of your app, you may need them all. And the debugging workflow can also benefit from tools like FlexiHub, that make it easier to provide testing resources by enabling developers to remote debug iOS devices.
